|Porting guide D3VE specific|
|Up to this date: August 15th of 2002, This porting guide has been somewhat generic.With no casting number specific information. As time progresses I will attempt to provide specific porting suggestions for each of the unique casting numbers that the FoMoCo produced.|
As a recap, the D3's have a modified valve seat depth that places the seats approximately .1" deeper in the chamber. No matter what the "Magazines" tell you the D3 chamber is not detonation prone and is almost exactly the same shape as the earlier castings.
The short turn / crest is significantly higher in these castings and this means that the required short turn shape is different.
I will outline a stock exit port that is less time consuming and easier to shape. Header flange fittment is a non issue with this port style, as the exit size and shape is very close to stock as cast specs.
After considerable time on a bench I have been able to get these castings to flow on parr with the D0VE-C's. The shape of the short turn is critical and is the difference between a 185 cfm port and a 200 cfm port.
My assumptions about these heads were not correct and I want to make sure that folks understand that these heads, when ported properly, give up nothing of note to the D0VE's. I'm sorry for the bad information. Glad it was temporary. This site privides information and is documentation of my evolution with regards to my understanding of these castings.I share all information I get and even some of my mistakes. I am no colledge educated engineering major I'm just regular people like most of you who come here.
I now have ported D3's in use that are supporting near 600 HP with a smallish 232 @ .050" lift and .565" lift cam. Do Not underestimate these castings. SMJ/11-03
I could find no great gains in flow potential by fully working the exit and roof of this port. In short don't work more than you have to.
The proper port shapes are shown with pics and differences will be noted. It is assumed that you have allready been through the step by step guide and seen the porting suggestions and architecture information. The stock exit porting info at the end of that section outlines why this port works and the consequences of removing some of the desireable shapes and goofy looking bumps.
Good luck and Happy grinding...